abstract：:Groups of Syrian hamsters were exposed to LD cycles with twilight transitions and photoperiods simulating natural lighting conditions at the summer solstice (SS), equinox, and winter solstice (WS) at 41 degrees N and at the winter solstice at the Arctic Circle (WS 66 degrees N) but with daytime illuminance truncated a...

journal_title：Journal of biological rhythms

authors： Boulos Z,Macchi MM

更新日期：2005-04-01 00:00:00

abstract：:To assess binocular interactions and possible ocular dominance in entrainment of circadian rhythms, Syrian hamsters maintained in LL were subjected for several weeks to schedules of eye occlusion with opaque contact lenses. In separate groups, the opaque lens was inserted into the left or right eye for 12 h at the sam...

journal_title：Journal of biological rhythms

authors： Park JH,Paul MJ,Butler MP,Zucker I

更新日期：2005-02-01 00:00:00

abstract：:On the southern Iberian Peninsula, the seasonal life history of the large white butterfly, Pieris brassicae, comprises 2 different photoperiodically induced developmental arrests: a hibernation diapause at photophases < 11 h and an estivation diapause at photophases > 14 h. At intermediate photophases (12 h to 13 h), ...

journal_title：Journal of biological rhythms

authors： Spieth HR,Xue F,Strau K

更新日期：2004-12-01 00:00:00

abstract：:The mammalian SCN contains a biological clock that drives remarkably precise circadian rhythms in vivo and in vitro. Recent advances have revealed molecular and cellular mechanisms required for the generation of these daily rhythms and their synchronization between SCN neurons and to the environmental light cycle. Thi...

journal_title：Journal of biological rhythms

authors： Hastings MH,Herzog ED

更新日期：2004-10-01 00:00:00

abstract：:The authors examined spatial working memory in the Morris water maze during the activity and rest periods of Wistar rats. Wheel-running activity was measured continuously as a marker of circadian phase. To minimize possible masking effects on performance, animals were placed in constant dim light the day before testin...

journal_title：Journal of biological rhythms

authors： Valentinuzzi VS,Menna-Barreto L,Xavier GF

更新日期：2004-08-01 00:00:00

abstract：:Arctic and subarctic environments are exposed to extreme light: dark (LD) regimes, including periods of constant light (LL) and constant dark (DD) and large daily changes in day length, but very little is known about circadian rhythms of mammals at high latitudes. The authors investigated the circadian rhythms of a su...

journal_title：Journal of biological rhythms

authors： Tavernier RJ,Largen AL,Bult-Ito A

更新日期：2004-06-01 00:00:00

abstract：:The authors analyzed the upstream regulatory region of purF, a gene that is expressed in a minority phase that peaks at dawn (class 2 circadian phasing) in Synechococcus elongatus, to determine whether specific cis elements are responsible for this characteristic expression pattern. Fusions of various promoter-bearing...

journal_title：Journal of biological rhythms

authors： Min H,Liu Y,Johnson CH,Golden SS

更新日期：2004-04-01 00:00:00

abstract：:A single light episode during the first larval stage can set the phase of adult Drosophila activity rhythms, showing that a light-sensitive circadian clock is functional in larvae and is capable of keeping time throughout development. These behavioral data are supported by the finding that neurons expressing clock pro...

journal_title：Journal of biological rhythms

authors： Malpel S,Klarsfeld A,Rouyer F

更新日期：2004-02-01 00:00:00

abstract：:An outstanding unresolved issue in chronobiology is how the level of locomotor activity influences length of the free-running, endogenous circadian period (tau). To address this issue, the authors studied a novel model, 4 replicate lines of laboratory house mice (Mus domesticus) that had been selectively bred for high...

journal_title：Journal of biological rhythms

authors： Koteja P,Swallow JG,Carter PA,Garland T Jr

更新日期：2003-12-01 00:00:00

abstract：:Hibernating animals have been a successful model system for elucidating fundamental properties of many physiological systems. Over the past 50 years, a diverse literature has emerged on the role of the circadian system in control and expression of winter torpor in several orders of birds and mammals. This body of rese...

journal_title：Journal of biological rhythms

authors： Ruby NF

更新日期：2003-08-01 00:00:00

abstract：:An understanding of the retinal mechanisms in mammalian photoentrainment will greatly facilitate optimization of the wavelength, intensity, and duration of phototherapeutic treatments designed to phase shift endogenous biological rhythms. A small population of widely dispersed retinal ganglion cells projecting to the ...

journal_title：Journal of biological rhythms

authors： Rollag MD,Berson DM,Provencio I

更新日期：2003-06-01 00:00:00

abstract：:Aging alters numerous aspects of circadian biology, including the amplitude of rhythms generated by the suprachiasmatic nuclei (SCN) of the hypothalamus, the site of the central circadian pacemaker in mammals, and the response of the pacemaker to environmental stimuli such as light. Although previous studies have desc...

journal_title：Journal of biological rhythms

authors： Kolker DE,Fukuyama H,Huang DS,Takahashi JS,Horton TH,Turek FW

更新日期：2003-04-01 00:00:00

abstract：:Perhaps the most observable of the many circadian oscillations that have been described in both vertebrate and invertebrate animals is the daily alterations in periods of rest and activity. Recent studies in the fruit fly Drosophila melanogaster suggest that these periods of inactivity are not simply rest but share ma...

journal_title：Journal of biological rhythms

authors： Shaw P

更新日期：2003-02-01 00:00:00

abstract：:From the mathematical study of simple models for circadian rhythm, the authors identified a clear effect of saturation in the enzyme kinetics on the promotion or suppression of a sustained oscillation. In the models, a clock gene (per gene) is transcribed to produce mRNAs, which are translated to produce proteins in t...

journal_title：Journal of biological rhythms

authors： Kurosawa G,Iwasa Y

更新日期：2002-12-01 00:00:00

abstract：:At least two major physiological systems are involved in the adaptation of the organism to environmental challenges: the circadian system and the stress reaction. This study addressed the possibility that interindividual differences in stress sensitivity and in the functioning of the circadian system are related. At 2...

journal_title：Journal of biological rhythms

authors： Weibel L,Maccari S,Van Reeth O

更新日期：2002-10-01 00:00:00

abstract：:Siberian hamsters transferred from a long (16 h light/day [16 L]) to an intermediate (13.5 L) day length (DL) undergo testicular regression within 2 months followed approximately 2 months later by "spontaneous" testicular recrudescence. Recovery of gonadal function after prolonged exposure to intermediate DLs is thoug...

journal_title：Journal of biological rhythms

authors： Kauffman AS,Zucker I

更新日期：2002-08-01 00:00:00

abstract：:The mammalian circadian pacemaker is located in the suprachiasmatic nucleus (SCN). Various inputs modulate pacemaker phase, including the serotonergic (5HTergic) input from the midbrain raphe. 5HT phase-advances the SCN pacemaker when applied during mid subjective day. In vitro studies indicate that 5HT advances the m...

journal_title：Journal of biological rhythms

authors： Jovanovska A,Prosser RA

更新日期：2002-04-01 00:00:00

abstract：:The purpose of this study was to determine whether decreased day lengths affect reproduction or the immune system in inbred mice. Irrespective of a nocturnal pineal melatonin rise, the signal for day length information, body and testis weights were the same in various strains 8 weeks after transfer from long to short ...

journal_title：Journal of biological rhythms

authors： Yellon SM,Tran LT

更新日期：2002-02-01 00:00:00

abstract：:The authors sought to investigate the role of phytochromes A and B (phyA and phyB) and cryptochromes 1 and 2 (cryl and cry2) in the synchronization of the leaf position rhythm in Arabidopsis thaliana. The seedlings were transferred from white light-dark cycles to free-running conditions with or without exposure to a l...

journal_title：Journal of biological rhythms

authors： Yanovsky MJ,Mazzella MA,Whitelam GC,Casal JJ

更新日期：2001-12-01 00:00:00

abstract：:Ground squirrels, Spermophilus tridecemlineatus, were kept in a 12:12 h light-dark cycle. As expected for a diurnal species, their locomotor activity occurred almost entirely in the daytime. Expression of mPer1 and mPer2 in the suprachiasmatic nucleus was studied at six time points by in situ hybridization. For both t...

journal_title：Journal of biological rhythms

authors： Mrosovsky N,Edelstein K,Hastings MH,Maywood ES

更新日期：2001-10-01 00:00:00

abstract：:Most of the anatomical and molecular substrates of the system that encodes changes in photoperiod in the duration of melatonin secretion, and the receptor molecules that read this signal, have been shown to be conserved in monkeys and humans, and the functions of this system appear to be intact from the level of the r...

journal_title：Journal of biological rhythms

authors： Wehr TA

更新日期：2001-08-01 00:00:00

abstract：:In Drosophila melanogaster, disruption of night by even short light exposures results in degradation of the clock protein TIMELESS (TIM), leading to shifts in the fly molecular and behavioral rhythms. Several lines of evidence indicate that light entrainment of the brain clock involves the blue-light photoreceptor cry...

journal_title：Journal of biological rhythms

authors： Ivanchenko M,Stanewsky R,Giebultowicz JM

更新日期：2001-06-01 00:00:00

abstract：:Morningness and eveningness preference, an endogenous component of the circadian clock, is characterized by an interindividual difference in circadian phase and requires of humans a specific timing of behavior. The biological rhythms of morning and evening types are consequently phase shifted with fixed socioeconomic ...

journal_title：Journal of biological rhythms

authors： Taillard J,Philip P,Chastang JF,Diefenbach K,Bioulac B

更新日期：2001-04-01 00:00:00

abstract：:The synchronizing stimulus, its transduction site, and the afferent pathways responsible for feeding entrainment remain unknown. In fish, the role of the diet in the development of feeding anticipatory activity (FAA) is not well understood and fundamental questions on the mechanisms of feeding entrainment, such as the...

journal_title：Journal of biological rhythms

authors： Sánchez-Vázquez FJ,Aranda A,Madrid JA

更新日期：2001-02-01 00:00:00

abstract：:Photoperiod influences the distribution of sleep and waking and electroencephalogram (EEG) power density in the Djungarian hamster. In an experimental procedure combining short photoperiod (SP) and low ambient temperature, the light-dark difference in the amount of sleep was decreased, and the changes in slow-wave act...

journal_title：Journal of biological rhythms

authors： Deboer T,Vyazovskiy VV,Tobler I

更新日期：2000-10-01 00:00:00

abstract：:A recent report that popliteal illumination shifted the circadian rhythms of body temperature and melatonin challenged the longstanding belief that light phase-shifting the circadian system in mammals is mediated only through the retina. The authors tested effects of popliteal illumination and illumination provided th...

journal_title：Journal of biological rhythms

authors： Jean-Louis G,Kripke DF,Cole RJ,Elliot JA

更新日期：2000-06-01 00:00:00

abstract：:Siberian hamsters are photoperiodic seasonally breeding rodents. To date, there has been no evidence that Siberian hamsters exhibit an annual rhythm in reproductive, thermoregulatory, molt, or body mass changes. However, given that the termination of their winter cycle is under endogenous control, the authors thought ...

journal_title：Journal of biological rhythms

authors： Anchordoquy HC,Lynch GR

更新日期：2000-04-01 00:00:00

abstract：:The classical power spectrum, computed in the frequency domain, outranks traditionally used periodograms derived in the time domain (such as the chi2 periodogram) regarding the search for biological rhythms. Unfortunately, classical power spectral analysis is not possible with unequally spaced data (e.g., time series ...

journal_title：Journal of biological rhythms

authors： Van Dongen HP,Olofsen E,VanHartevelt JH,Kruyt EW

更新日期：1999-12-01 00:00:00

abstract：:Numerous studies have used the classic van der Pol oscillator, which contains a cubic nonlinearity, to model the effect of light on the human circadian pacemaker. Jewett and Kronauer demonstrated that Aschoff's rule could be incorporated into van der Pol type models and used a van der Pol type oscillator with higher o...

journal_title：Journal of biological rhythms

authors： Forger DB,Jewett ME,Kronauer RE

更新日期：1999-12-01 00:00:00

abstract：:We examine theoretical models for circadian oscillations based on transcriptional regulation in Drosophila and Neurospora. For Drosophila, the molecular model is based on the negative feedback exerted on the expression of the per and tim genes by the complex formed between the PER and TIM proteins. For Neurospora, sim...

journal_title：Journal of biological rhythms

authors： Leloup JC,Gonze D,Goldbeter A

更新日期：1999-12-01 00:00:00

abstract：:Little is known about the differences in the neural substrates of circadian rhythms that are responsible for the maintenance of differences between diurnal and nocturnal patterns of activity in mammals. In both groups of animals, the suprachiasmatic nucleus (SCN) functions as the principal circadian pacemaker, and sur...

journal_title：Journal of biological rhythms

authors： Nunez AA,Bult A,McElhinny TL,Smale L

更新日期：1999-08-01 00:00:00

abstract：:The human circadian timing system has previously been shown to free run with a period slightly longer than 24 h in subjects living in the laboratory under conditions of forced desynchrony. In forced desynchrony, subjects are shielded from bright light and periodic time cues and are required to live on a day length out...

journal_title：Journal of biological rhythms

authors： Kelly TL,Neri DF,Grill JT,Ryman D,Hunt PD,Dijk DJ,Shanahan TL,Czeisler CA

更新日期：1999-06-01 00:00:00

abstract：:Nonphotic stimuli can reset and entrain circadian activity rhythms in hamsters and mice, and serotonin is thought to be involved in the phase-resetting effects of these stimuli. In the present study, the authors examined the effect of the serotonin agonist quipazine on circadian activity rhythms in three inbred strain...

journal_title：Journal of biological rhythms

authors： Kohler M,Kalkowski A,Wollnik F

更新日期：1999-04-01 00:00:00

abstract：:Transplantation of the fetal suprachiasmatic nucleus (SCN) in arrhythmic SCN-lesioned rats can reinstate circadian drinking rhythms in 40% to 50% of the cases. In the current article, it was investigated whether the failure in the other rats could be due to the absence of a circadian rhythm in the grafted SCN, using a...

journal_title：Journal of biological rhythms

authors： van Esseveldt KE,van der Geest BA,Duindam H,Rietveld WJ,Boer GJ

更新日期：1999-02-01 00:00:00

abstract：:Systematic treatment of hamsters with triazolam (TRZ) or novel wheel (NW) access will yield PRCs similar to those for neuropeptide Y. Both TRZ and NW access require an intact intergeniculate leaflet (IGL) to modulate circadian rhythm phase. It is commonly suggested that both stimulus types influence rhythm phase respo...

journal_title：Journal of biological rhythms

authors： Meyer-Bernstein EL,Morin LP

更新日期：1998-12-01 00:00:00

abstract：:The possibility that feeding may act as a zeitgeber has been investigated in captive Svalbard ptarmigan by recording feeding or food-searching activity (FA) in birds given periodic access to food (PAF) under light-dark (LD) cycles or in continuous bright (LL) or dim light (DD) conditions. Except during LL, anticipator...

journal_title：Journal of biological rhythms

authors： Reierth E,Stokkan KA

更新日期：1998-10-01 00:00:00

abstract：:The authors have shown previously that vasopressin (VP) release from suprachiasmatic nucleus (SCN) efferents in rats is important for the timing of the circadian activity of the hypothalamo-pituitary-adrenal (HPA) axis, resulting in a circadian rise in corticosterone at dusk. When meals are supplied at a fixed time du...

journal_title：Journal of biological rhythms

authors： Kalsbeek A,van Heerikhuize JJ,Wortel J,Buijs RM

更新日期：1998-02-01 00:00:00

abstract：:Numerous studies have demonstrated sleep-promoting effects of melatonin treatment in humans, as evidenced by subjects' self-reports, polysomnographic recordings, and continuous actigraphic registration of motor activity. The sleep-promoting effects of either physiological or pharmacological doses of melatonin typicall...

journal_title：Journal of biological rhythms

authors： Zhdanova IV,Wurtman RJ

更新日期：1997-12-01 00:00:00

abstract：:The endogenous circadian rhythm of melatonin in humans provides information regarding the resetting response of the human circadian timing system to changes in the light-dark (LD) cycle. Alterations in the LD cycle have both acute and chronic effects on the observed melatonin rhythm. Investigations to date have firmly...

journal_title：Journal of biological rhythms

authors： Shanahan TL,Zeitzer JM,Czeisler CA

更新日期：1997-12-01 00:00:00

abstract：:The tau mutation in Syrian hamsters (Mesocricetus auratus) is phenotypically expressed in a period of the circadian rhythm of about 20 h in homozygotes (SS) and about 22 h in heterozygotes (S+). The authors investigate whether this well-defined model for variation in circadian period exhibits associated changes in ene...

journal_title：Journal of biological rhythms

authors： Oklejewicz M,Hut RA,Daan S,Loudon AS,Stirland AJ

更新日期：1997-10-01 00:00:00